Problem: Balance the following chemical equation: $ $ $\text{SiO}_2 +$ $\text{HF} \rightarrow$ $\text{SiF}_4 +$ $\text{H}_2\text{O}$
Explanation: There is $1 \text{ Si}$ on the right and $1$ on the left, so $\text{Si}$ is already balanced. There are $2 \text{ O}$ on the left and only $1$ on the right, so multiply $\text{H}_2\text{O}$ by ${2}$ $ \text{SiO}_2 + \text{HF} \rightarrow \text{SiF}_4 + {2}\text{H}_2\text{O} $ Now there are $4 \text{ H}$ on the right and only $1$ on the left, so multiply $\text{HF}$ by ${4}$ $ \text{SiO}_2 + {4}\text{HF} \rightarrow \text{SiF}_4 + 2\text{H}_2\text{O} $ Now $\text{F}$ is balanced too. The balanced equation is: $ \text{SiO}_2 + 4\text{HF} \rightarrow \text{SiF}_4 + 2\text{H}_2\text{O} $